window.onload=function(){
    // var search=document.getElementById('fixedBox');
    var body=document.getElementsByTagName('body')[0];
    body.setAttribute('onscroll','scrollSearch()');
}
function scrollSearch(){
    var search=document.getElementById('fixedBox');
    var st = document.documentElement.scrollTop || document.body.scrollTop
    console.log(st);
    if(st>=48){
        search.style.position='fixed';
        search.style.top=0;
        search.style.zIndex=999;
    }else{
        search.style.position='';
        search.style.top=0;
        search.style.zIndex=0;
    }
}
